Robotic grouter

This application is a U.S. national stage application of International Application No. PCT/SG2023/050128, filed Mar. 3, 2023; which application claims priority to Singapore Application Ser. No. 10/202,202458V, filed Mar. 10, 2022.

The present disclosure relates to grouting of tiles. In a particular form the present disclosure relates to a robotic grouter for grouting tiles.

After tiles are installed on a surface, grout is typically inserted to fill the gaps between adjacent tiles (or between edge tiles and a wall). Grout is fluid mixture which sets hard and is typically a cement based fluid mixture comprised of water, cement and depending upon the application, additives such as sand and polymers. Epoxy and polymer grouts are also used in certain applications, Grout is used to add mechanical strength to tiles (i.e. to support the edges and to keep them spaced apart); to protect the surface beneath the tiles; and to improve the visual appearance of the tiles.

Installing grout is laborious process in which a tool such as a trowel or grout float to push grout into the gaps. The excess grout is then progressively cleaned off the tiles using a sponge or cloth (taking care not to disrupt/remove the grout between the tiles). Given the manual and laborious nature of the task, various attempts have been made to develop improved tools and apparatus (including automated robots). However this is a challenging task as grouting must be performed on a wide range of tiles of different sizes, shapes and colours laid in a wide range of geometrical configurations. In particular, the perimeter size and shape varies significantly, and care must be taken with grouting in edges to avoid grout on walls or surrounding areas. Further the grouting must be performed in a wide range of lighting and environmental conditions (e.g. indoor and outdoor locations). Accordingly many of the tools or apparatus developed to date only useful for specific tasks such as cleaning a sponge, or operating in large open areas away from boundaries. As such they remain inefficient compared to an experienced human grouter/tiler with a trowel and sponge that is more versatile and able to grout a range of different tiles (including into corners and edges) in a range of locations and environments.

There is thus a need to provide improved automated systems for grouting tiles, or to at least provide a useful alternative to existing systems.

According to a first aspect, there is provided an autonomous grouting robotic apparatus comprising:

In one form, the slot of the nozzle ends in a nozzle tip, and when viewed from the side, a front face of the nozzle is inclined rearward with respect to the nozzle tip and the vertical axis such that an angle from the grouting line to the front face is greater than 90 degrees, and when viewed from the front the nozzle has a symmetrical chamfered profile such that a left side and a right side each define an opening angle with the vertical axis of less than 45 degrees.

In a further form, the slot comprises a plurality of gaps each separated by projection separator that protrudes out of the slot to compress grout into the tile gap.

In one form, the grout extruder mounting assembly is mounted on the front sponge guide assembly such that tilting the front sponge guide assembly also tilts the grout extruder mounting assembly.

In a further form, the grout storage container is a grout cartridge and the grout extruder mounting assembly comprises a lower mount and an upper mount, wherein the lower mount has an inverted U shaped profile such that when mounted to the front sponge guide assembly the arms of the U define a gap through which the belt passes, and the upper mount is configured to support the grout cartridge and comprises a pair of guide rails which extend rearward of the upper mount and are connected to an end cap which supports the motorised plunger arrangement, and a linear actuator arrangement is configured to control extension and retraction of the grout cartridge along the guide rails to control a location of the nozzle tip with respect to a front face the upper mount, and wherein the upper mount is configured to be driven away from the lower mount so as to control an orientation of the nozzle tip as the front sponge guide assembly is tilted.

In one form, the front sponge guide assembly comprises a main support structure on which the grout extruder mounting assembly is mounted, and a plurality of rollers that defines a forward belt path around the main support structure comprising a first front powered roller to receive and drive the belt, a tip roller located distal of the front powered roller with a smaller diameter than the front powered roller to define the forward tip and guide the belt over and then under the front powered roller and towards a rear guide roller for guiding the belt back towards the sponge belt cleaning and tensioning assembly.

In a further form, the frame comprises a body frame and a front frame extending forward of the body frame, and the front support assembly comprises a first support structure mounted to the front frame which supports a pivot arrangement and a second support structure which supports the front sponge guide assembly, wherein a height of the second support structure is adjustable with respect to the first support structure, and the pivot arrangement comprises a front pivoting mount that supports a front pivoting roller and a rear roller wherein the front pivoting roller guides the sponge belt coming from the sponge belt cleaning and tensioning assembly towards the front powered roller and the rear roller receives the sponge belt from the rear guide roller and direct the belt to the sponge belt cleaning and tensioning assembly, and the front sponge guide assembly is connected to the front pivoting mount, and tilting of the front sponge guide assembly is driven by the second support structure which causes pivoting of the front pivoting mount and front pivoting roller.

In a further form the rear roller is a pivoting roller which is independently pivotable with respect to the front pivoting roller such that a pivot angle of the rear roller may be different to a pivot angle of the front pivoting roller. In a further form the apparatus further comprises a set of cascading pivoting rollers, wherein each roller in the set of cascading pivoting rollers is pivotable such that a total pivot angle or a pivoting range of the cascading pivoting rollers is larger than a pivot angle or a pivoting range of each individual pivoting roller, and either the set of pivoting rollers comprises the front pivoting roller and one or more additional pivoting rollers, or the set of pivoting rollers comprises the rear roller and one or more additional pivoting rollers and the rear roller is also a pivoting roller that is independently pivotable with respect to the front pivoting roller such that a pivot angle of the rear roller may be different to a pivot angle of the front pivoting roller, or the set of pivoting rollers comprises two sets of pivoting rollers, the first set comprising the front pivoting roller and one or more additional pivoting rollers and the second set of pivoting rollers comprises the rear roller and one or more additional pivoting rollers and the rear roller is also a pivoting roller that is independently pivotable with respect to the front pivoting roller such that a pivot angle of the rear roller may be different to a pivot angle of the front pivoting roller.

In a further form, the second support structure comprises a left frame and a right frame, and one or more guide rails that extend between the left and right frames and pass through apertures in the main support structure of the front sponge guide assembly and a threaded rod extends between the left and right frames and passes through a threaded nut in a horizontal slide arrangement in the main support structure of the front sponge guide assembly and one or both of the left and right frames comprises a motor arrangement to drive rotation of the threaded rod which drives the threaded nut along the threaded rod such that the horizontal slide arrangement translates horizontal movement into a rotation and tilting of the front sponge guide assembly, and a plurality of guide rods and one or more threaded rods connect the first support structure to the second support structure and one or more motors drive rotation of the threaded rods to adjustment the height of the first support structure with respect to the second support structure.

In one form, the frame comprises a body frame and a front frame extending forward of the body frame and the at least one imaging sensor comprises at least two imaging sensors which observe a composite field of view wherein at least one sensor is mounted to a distal end of the front frame in a forward direction and at least one imaging sensor is mounted to the distal end of the front frame in a downward direction.

In one form, the plurality of rollers direct the sponge belt through a serpentine path within the cleaning and tensioning assembly and the plurality of rollers comprises a plurality of squeezing rollers, a plurality of rinsing rollers a plurality of powered drive rollers and a plurality of tensioning rollers, wherein at least two of the plurality of squeezing rollers are located in the tank and receive the sponge belt from the front support assembly and are configured to squeeze grout out of the sponge belt and direct the sponge belt towards the plurality of rinsing rollers which are located in the tank, and at least one of the tensioning rollers directs the sponge belt out from the sponge belt cleaning and tensioning assembly towards the front pivoting roller and each of the tensioning rollers are mounted to a motor configured to adjust a position of the tensioning roller to control a tension in the sponge belt.

In one form, the control system is configured to:

In a further form, the motion sensors comprises one or more odometry sensors configured to monitor rotation of one or more wheels of the autonomous grouting robotic apparatus.

In a further form, identification of grout lines is performed after mapping the room using the SLAM algorithm.

In a further form, when identifying the plurality of grouting lines and when updating the precise location and the rotation angle, the plurality of images are processed by a computer vision method to identify a plurality of lines, and the plurality of lines are then split by angle into a plurality of buckets where each bucket is of a pre-determined angular range and for each bucket, an average direction of the lines in the bucket is determined, and the middle of each line in the bucket is projected on a norm of an average direction of the bucket to obtain a projected point, and the lines are clustered by the projected points where each cluster corresponds to a single real grouting line whose direction and center is set to the median direction and center of the lines in the cluster.

In a further form, the pre-determined angular range of each bucket is 15 degrees.

In one form the apparatus further comprises a marker, wherein the marker is adapted to be mounted to the nozzle or the grout extruder is configured to receive a removable marker cartridge comprising a marker, and the control system is further configured to mark out a tiling map using the marker based on a tiling plan stored by the at least one memory.

In a further form the control system is configured to generate the tiling plan after generating a map of the room according to one or more design criteria.

According to a second aspect, there is provided a method of controlling an autonomous grouting robotic apparatus comprising:

In one form, the motion sensors comprise one or more odometry sensors configured to monitor rotation of one or more wheels of the autonomous grouting robotic apparatus.

In a further form, identification of grout lines is performed after mapping the room using the SLAM algorithm.

In one form, when identifying the plurality of grouting lines and when updating the precise location and the rotation angle, the plurality of images are processed by a computer vision method to identify a plurality of lines, and the plurality of lines are then split by angle into a plurality of buckets where each bucket is of a pre-determined angular range and for each bucket, an average direction of the lines in the bucket is determined, and the middle of each line is projected on a norm of an average direction of the bucket to obtain a projected point, and the lines are clustered by the projected points where each cluster corresponds to a single real grouting line whose direction and center is set to the median direction and center of the lines in the cluster.

In a further form, the pre-determined angular range of each bucket is 15 degrees.

In one form the method further comprises generating a tiling plan after generating a map of the room according to one or more design criteria.

According to a third aspect there is provided an autonomous tile marking robotic apparatus comprising:

In one form the control system is configured to generate the tiling plan after generating a map of the room according to one or more design criteria.

According to a fourth aspect there is provided a method of controlling an autonomous tile marking robotic apparatus comprising:

In one form the method further comprises comprising generating the tiling plan after generating a map of the room according to one or more design criteria, the tiling plan comprising a plurality of marking locations.

According to a fifth aspect, there is provided a computer readable medium comprising instructions for causing a processor to implement the method of the second or fourth aspects.

In the following description, like reference characters designate like or corresponding parts throughout the figures.

Referring now to, there is shown isometric, front, top and side views of an autonomous grouting robotic apparatusaccording to an embodiment.

The autonomous grouting robotic apparatuscomprises a framewhich supports the various components of the autonomous grouting robotic apparatus including a grout cleaning arrangement, a grout extruder, a power system, a drive systemand a control system.

In this embodiment the frame comprises a body frame, and a forward frame. The forward frame comprises left and right frame members connected via an are shaped linking support frame memberon which multiple cameras (each including imaging sensors) are mounted, including a centrally mounted forward viewing camera, and two downward viewing camerasandat either ends of the linking support frame member where it meets left and right frame members. A composite field of viewis obtained from combining the individual overlapping field of views. The composite field of view captures the downward view directly in front of the robot where grout is to be injected or cleaned, as well as a forward view of the grouting line to the tile edge or wall and which may include adjacent grouting lines and walls or edges. The composite field of viewis illustrated by dotted lines in. A casing or housing may be placed over the frame, but is not shown in order to illustrate the internal components.

The grout cleaning arrangementcomprises a sponge belt, a water tank, a sponge belt cleaning and tensioning assemblycomprises a plurality of rollers mounted within a tower structure, a front sponge guide assemblyand a front support assembly. The sponge belt cleaning and tensioning assembly comprises two towerseach mounted on the side frame members of the body frame(which extend to become the left and right forward frame members) via a holding structure. The water tankis similarly mounted to the side frame members via tank supportsand locked in place using tank locks. The sponge beltis looped and passes through the sponge belt cleaning and tensioning assemblywhere it is directed to the front sponge guide assembly which is configured to guide the sponge belt over a forward tip () and then back to the sponge belt cleaning and tensioning assembly. The front support assembly is mounted to the frameand is configured to both support the front sponge guide assemblyand to control a height of the front sponge guide assemblyand a tilt angle θ of the front sponge guide assembly with respect to a vertical axisof the autonomous grouting robotic apparatus.

The grout extrudercomprises a grout extruder mounting assemblywhich either supports a grout storage containeror is configured to receive and support a removable grout storage container, and a motorised plunger. The grout storage containerends in a nozzlewith a slotand is configured to receive the motorised plunger. The grout extruder mounting assembly is further configured to control a location and a height of the nozzleand to control a tilt angle θ of the nozzle with respect to a vertical axisof the autonomous grouting robotic apparatus. In this embodiment the grout extruder mounting assembly is mounted onto the front sponge guide assembly such that tilting the front sponge guide assembly also tilts the grout extruder mounting assembly (i.e. tilt in tandem).

A dry boxmounted in the rear of the body framehouses the components of the power system, drive systemand control system. The power system is configured to supply and regulate power to the various components including motors, imaging sensors (including cameras), LIDAR, sensors and processors, and includes components such as batteries, voltage converters, regulators, etc.. The drive systemis configured to drive the autonomous grouting robotic apparatus and in this embodiment comprises drive motors within the dry box, which drive a drive shaft (or axle), which drives wheelslocated at the front of the body framevia drive belts. Free spinning rear wheelsare located at the rear of the body frame. Placing these components in a dry box enables the apparatus to be easily cleaned by spraying the robot down with a hose.

The control systemcomprises at least one processor, at least one memory, at least one LIDAR, at least one imaging sensor, and one or more motion sensors. The imaging sensors are mounted to the frame (or other components) to observe a composite field of viewin front of the autonomous grouting robotic apparatus. In the context of this specification a composite field of view refers to a field of view that includes a downward viewing portion as well as a forward viewing portion. The downward viewing portion captures to a region directly in front of the robot to view the grouting line to be grouted or cleaned, and the nozzle or cleaning belt during grouting and cleaning operations. The forward viewing portion captures the grouting line as it extends forward of the robot towards the edge of the tiles and adjacent surroundings which may include adjacent and intersecting grouting lines, as well as walls and edge of the tiles. In some embodiments the imaging sensor is a camera comprising an imaging sensor and associated optical assemblies including one or more lenses to project or direct light onto the imaging sensor. In some embodiments a camera may include multiple image sensors each with an optical assembly such that each imaging sensor has a different field of view and/or different magnification. In some embodiments multiple optical assemblies may be used to project or direct light onto a single image sensor such that it has a composite field of view such that different regions of the imaging sensor capturing different views. In some embodiments the imaging sensor may include an optical assembly with a wide angle (e.g. fish eye) lens (or lenses) to generate a composite field of view comprising forward and downward looking views. In the context of this specification the term composite field of view will encompass an imaging sensor with a wide angle lens that optically combines a forward view and a downward view. In embodiments with a single imaging sensor the composite field of view may be obtained using an optical assembly with a wide angle or fish eye lens, or an optical assembly using multiple lens assemblies where each optical assembly points in a different direction (eg down and forward) and each project onto a different portion of the sensor. In embodiments with multiple imaging sensors, each imaging sensor is mounted to view a different field of view. For example in the example show in, a first camerahas a forward looking view mounted on the centre of the linking support frame member, and two downward looking camerasandat the ends of the linking support frame member. These views are combined to form a composite field of view. The motion sensors, such as odometry sensors configured to monitor rotation of the wheels, are configured to detect motion of the autonomous grouting robotic apparatus. The control system is configured to use at least a plurality of images and a plurality of LIDAR scans to identify a plurality of grouting linesin a room where each grouting line corresponds to a gap between tiles. The control system is configured to control the drive system, the grout extruder and the grout cleaning arrangement to control extrusion of the grout from the nozzle and to clean excess grout off tiles, such that when extruding grout the slot is aligned along the grouting line. This includes control of tilting of the grout extruderand the front sponge guide assembly to allow extrusion (and cleaning) of grout into edges and corners.

This is further illustrated in, which show isometric, front, top and side views of the autonomous grouting robotic apparatusin a tilted orientation. As noted above, because the grout extruder mounting assembly is mounted on the front sponge guide assembly the two tilt in tandem.show isometric, front, top and side views of the autonomous grouting robotic apparatus in a configuration with a retracted grout extruder and a lifted sponge belt, andshow isometric, front, top and side views in a configuration with a retracted grout extruder and a lowered sponge belt.

The grout extruder is further illustrated inwhich show isometric, front, top, side and rear views of the grout extruder including the grout extruder mounting assemblyand the grout storage containerwhich in this embodiment is a syringe like grout cartridge.is a sectional view through section AA ofandis a sectional view through section BB of.

The grout extruder mounting assemblycomprises a lower mountand an upper mount. In this embodiment the lower mountis attached to the main support structureof the front sponge guide assembly. As noted above this assists in synchronizing movement of the grouting extruder with the sponge belt cleaning mechanism. The upper mountis configured to be driven away from the lower mountso as to further control an orientation of the nozzle tip as the front sponge guide assemblyis tilted. Trapezoidal threaded rodsthat are connected to stepper motors (or equivalent) inand are used to adjust the distance betweenandand a threaded nut is used to connecttothrough the trapezoidal threaded rod. As the mechanism tilts from the centre position to the inclined, the distance between the tip and the pivot axis increases as the tilt angle changes from 0 degrees to 45 degrees, and this adjustment allows the control system to compensate for this distance change. We further note that the upper mountcomprises two identical components so that the upper support portion is symmetrical about the centre of the extrusion mechanism. Upper mountis also attached to front pivoting mountso that it pivots together with the rest of the structure.

The lower mounthas an inverted U shaped profile such that when mounted to the front sponge guide assemblythe arms of the U define a gap through which the sponge beltpasses. The upper mountis also configured to support the grout cartridgeand comprises a pair of guide railswhich extend rearward of the upper mount and are connected to an end capwhich supports the motorised plunger arrangement

A linear actuator arrangement is configured to control extension and retraction of the grout cartridge along the guide rails to control a location of the nozzle tipwith respect to a front face the upper mountas shown in. This is enabled by trapezoidal threaded rodsfixed toon one side and end capon the other. This is to help move the grout cartridgeup and down the railsas it extends and retracts, as to extrude grout the cartridge must extend out to the level of the sponge belt where the grout lineis located. Conversely, when it is not extruding grout, the grout cartridge can be retracted and lifted off the ground when no longer needed. When tilted and grouting in a corner the cartridge is extended more than when it is grouting a centre grout line. Also, at the end of a grout lineperpendicular to the wall, it should also have enough leeway to retract such that the front most point of the grouting mechanism is behind the tip of the sponge belt. This is so that the sponge belt can reach the end of the grout line and clean the entire grout line effectively without anything getting in the way. This trapezoidal threaded rodis fixed in place allowing a rotating nut to instead drive the motion. Guide railsare used for radial structural support and are attached to end cap, the grout cartridge, and upper mount

Extrusion of grout is controlled by the control system. Specifically a threaded nutis attached to a timing belt pulleyis used to drive trapezoidal threaded rod. A timing beltis attached toand a timing belt pulleythat is attached to a stepper motor stored in a housingthat is used to drive trapezoidal threaded rod. A tensioning mechanismis used to tension timing belt. Trapezoidal threaded rodis attached to plungerand a non-captive stepper motor to move it up and down. The grout cartridge is used to store and extrude the grout. When the plungeris fully retracted, the grout is loaded. When grout is being extruded, the stepper motorpushes the plungerthrough the trapezoidal threaded rodlike a linear actuator with precision so that a precise amount of grout can be extruded when needed. A guide railis also used for the plunger. As the plunger extrudes, the guide rail will gradually enter the syringe mechanism. As the trapezoidal threaded rodis solidly attached to plunger, it is prevented from spinning to allow the non-captive stepper motor to drive linear rather than rotational motion. The external structure of the grouting mechanismis used to support the grout cartridgeand allows the grout cartridgeand the nozzleto be easily detached and reloaded or replaced as necessary.

The grout cartridgeis further illustrated inwhich show isometric, front, top, and side views.are sectional views through sections AA, BB and CC of. As shown in these figures, the slot of the nozzleends in a nozzle tip. The grouting nozzle planeis the plane that would be parallel to the grout lines/grout surface and contains the opening where the grout is extruded.

When viewed from the side such as shown in, a front faceof the nozzle is inclined rearward with respect to the nozzle tipand the vertical axissuch that an angle from the grouting line to the front face is greater than 90 degrees (in this embodiment 95.45 degrees). This is so that the nozzle tip is able to reach the end of a given grout line flush to the wall without anything obstructing the nozzle (i.e. getting in the way).